I had some people asking me about these in another thread so I thought I'd post a tute. I've been making them since my grandma showed me how when I was about 10 years old. I'm still using her original templates! They are super easy and super versatile!

This is my first photo tute for anything so please bear with me.
materials:

butterfly template (see below)
scissors
pen/pencil(for tracing)
assorted papers (its best to keep these thin, wrapping paper or magazine pages are perfect, scrapbooking paper works too, just make sure it isn't too heavy or you ill have a hard time folding it)
Thread or wire (either of these work, thin gauge wire is best if you want to add beads or antennae. I like using decorative threads like the metallic thread I've used in this tute)
Beads/stick on gems/glitter (for embelishing. These are up to you and entirely optional)
Step 1:

download and printout the template. The original templates are 18cm long (large) and 8cm long (small) but play with the size to get different sized butterflies. The grid in my background is 1 inch square to give you a clue to the finished size. There are two templates available, I use both. The large butterfly was used for the butterfly on the card and the large pink butterfly in the first picture. It has a wider, more pointed look. The small butterfly template has a more rounded look. It's up to you which one you use. Cut out your chosen template. If you plan on making on lot of butterflies it helps to cut your template out of acetate or thin cardboard.
Step 2:

trace the template onto your chosen paper and cut it out.
Step 3:


With your shape cut out fold a strip down, roughly 5mm. Fold this strip back on itself in an accordian fashion. Continue to accordion fold down the length of the shape.
Step 4:


When you have finished folding the shape fold it in half to gauge the middle of the strip. Cut a length of thread or wire. tie the thread around the middle of the folded strip. If using wire, wrap the wire around the folded strip and twist the ends together.
Step 5:


Using your fingers gently fan out one side of the folded strip. This form one butterfly wing. Repeat on the other side. You may need to move the thread or wire gently to one side to even out your butterfly.
Your butterfly is now finished! You can decorate your butterfly by adding beads, gems or glitter. You can stick your butterfly to cards or journals etc. I like to add them to the tops of presents as decorations.

If you don't understand aything, just ask. I'd love to see your buterflies if you make any!
-Ralph